“…(liquid film) 2 830, 1730 (CO,R), 1 380 and 1 370 [(OMe),], and 750 and 699 cm-' (Ph); 6 , (250 MHz; CDCl,) (a-epimer) 1.31 (3 H, s, Me), 1.43 (3 H, s, Me), 1.9-2.0 (2 H, m, 5-H,), 2.22 (1 H, dtd, J 10,9, and 5 Hz, 4-H), 2.97 (1 H, br t, J4. 5 N-( 2-Pyridylmethyl)-4~-dimethoxymethyl-2a,3a-( isopropylidenedioxy)cyclopentune-1 P-curboxumide (15).--To a solution of the acid (6) (1.2 g, 4.62 mmol) in dry dichloromethane (75 ml) was added a solution of 2-(aminomethy1)pyridine (0.56 g, 5.18 mmol) in dichloromethane (6 ml) followed by DCC (0.98 g, 4.75 mmol). The resulting solution was stirred under nitrogen for 1 h, then filtered to remove dicyclohexylurea, and the solvent was removed.…”